One existing approach to electronic signatures provides an electronic signature “stamping” application for a mobile device. The signature application allows a user to open a document sent to them for signing and “stamp” a signature or other data into the document and return this by email. This approach suffers from a number of drawbacks. As one example, it only works with specific software applications for mobile devices, and the signing process is performed entirely in software on the mobile device. As such, the document must be manually moved from the email message into the device, manipulated, and then returned back to the device for email delivery. Also, to produce such an application for multiple devices or platforms requires that a largely redundant application be built for every platform, and then only for those platforms that have enough capability to actually manipulate PDFs. Not all platforms or devices can actually handle tasks like conversion of files, presentation of files, managing signature capture and placement and security. The inability of mobile devices to universally perform all such required functions severely limits the expansion of electronic signature services, particularly in the mobile device context.